Here you will find complete information about websites and portals where you can find FREE GIS, Remote Sensing, spatial and hydrology data as a service, also tons of interesting articles, tutorials and reviews about GIS, Remote Sensing and Spatial Hydrology data and data warehouses where you can download spatial data FREE with a minimum effort. For an example where you can directly download FREE spatial data which are been catalogued by Global, Regional, Continent, Country and river basin wise.

24 May 2016

Smart web-based tools for some coordination conversion routines. The State Plane Coordinate system provides coordinates on a flat grid for easy computation while maintaining a difference between geodetic and grid distance of one part in 10,000 or better. The utilities in this package provide methods for converting between Geodetic Positions and State Plane Coordinates.

The State Plane Coordinate system divides the U.S. into a hundred or more distinct grid surfaces (Zones). Do not mix coordinates from one Zone with that in another. In you need to cross Zone boundaries, use Geodetic Positions. The utilities in this package provide methods for converting between Geodetic Positions and State Plane Coordinates or for finding an SPC Zone.This utility uses NGS program SPCS83 or program GPPCGP to convert NAD83 or NAD27 Geodetic Positions to State Plane Coordinates (SPC)

Converts NAD 83 state plane coordinates to NAD 83 geographic positions and conversely. Includes defining constants for NAD 83 coordinate zones. State plane coordinates are entered or computed to 1 mm accuracy, while the latitudes and longitudes entered or computed correspond to approximately 0.3 mm accuracy.

23 May 2016

NCAR's GIS Initiative Climate
Change Scenarios GIS data portal. This portal is intended to serve a community
of GIS users interested in climate change. The
free datasets of climate change projections can be viewed on-line and/or
downloaded in a common GIS (shapefile) or text file format. Many 2D variables
from modelled projected climate are available for the atmosphere and land
surface. These climate change projections were generated by the NCAR Community
Climate System Model, or CCSM, for the 4th Assessment Report of the
Intergovernmental Panel on Climate Change (IPCC).

What’s New?

·In addition to global CCSM climate projections,
downscaled projections of monthly mean temperature and total precipitation for
the contiguous United States are now available. The downscaled dataset was
produced using a statistical downscaling method.

·Climate change projections from the Community
Climate System Model (CCSM-3) are generated on a Gaussian grid, which is
commonly used in scientific modeling. With a Gaussian grid, each grid point can
be uniquely accessed by one-dimensional latitude and longitude arrays (i.e. the
coordinates are orthogonal). In the CCSM model output, distributed here, the
longitudes are equally spaced at 1.40625º, while the latitudes vary in spacing
from 1.389º to 1.400767º. Due to irregular nature of the gridded CCSM model
output this portal distributes the datasets in a point shapefile format, where
each point represents a centroid of a corresponding CCSM grid cell. To more
accurately represent a continuous surface of global climate, we are providing a
global /polygon /dataset for use with the CCSM modeled climate projections.
This polygon layer was derived using the 4 corner coordinates, based on
latitude and longitude, for each grid cell of the CCSM outputs. This creates
irregular, rectangular polygons, as in a Gaussian grid of the original model
output. Click here for more information.

·A tutorial on how to analyze climate projections
from the CCSM in a GIS is now available. In this demonstration, we compare
model output of a present-day climate simulations with future climate
projections. To download the tutorial, click here.

The mobile market is made up of laptops, smartphones, and tablets. Historically dominated by the iPhone and iPad, new launches by other manufacturers have started to challenge Apple's preeminence. The most popular platforms (mobile operating systems) are Apple's iOS, Android, Symbian, Windows, and BlackBerry. Mobile device screen size is an important application development and design consideration. Screen sizes range from the 2.6-inch HP Veer through the 3.5-inch iPhone and 9.7-inch iPad 2 to the 10.1-inch Samsung Galaxy Tab. Any ArcGIS map viewer needs to be designed with the screen size in mind. Larger screen sizes lend themselves to more complex applications.

Accessing Mobile Applications

There are two ways to access applications on a mobile device. The first is to simply fire up the mobile web browser and access an existing web application. From a user's perspective, there are disadvantages to this approach. Arguably the biggest is the inability to access applications built using Adobe Flash/Flex or Microsoft Silverlight from any Apple iOS device. This relates to Apple's restrictions on installing plug-ins such as the Flash player. Thus the Esri 2.3.1 Flex viewer can be accessed from most mobile devices, but not the iPhone or the iPad 2. Apple is by no means alone in imposing these types of restrictions.

ArcGIS for Mobile: Development Process

The next part of the discussion focuses on the development process: from rough design to application framework to actual coding. From a programmer's perspective, this is where the fun begins. For clients and users, it is (hopefully) the evolution of a new and useful tool. This article was written in conjunction with the actual development of the application. It includes thoughts about this process as well as idle thoughts about developing mobile apps...

Those who are looking for higher resolution DEM, I have a very good news to convey.All ASTER data products are now available at no charge to all usersNow, NASA/METI released the 30m global (83°N and 83°S and is composed of 22,600 1°-by-1° tiles) ASTER GDEM based on 1,264,118 single ASTER dems from 1.4 million scenes in total. 95% vertical ci: 20 meters, 95% horizontal ci: 30 meters)ASTER GDEM is an easy-to-use, highly accurate DEM covering all the land on earth, and available to all users regardless of size or location of their target areas. Anyone can easily use the ASTER GDEM to display a bird's-eye-view map or run a flight simulation, and this should realize visually sophisticated maps. By utilizing the ASTER GDEM as a platform, institutions specialized in disaster monitoring, hydrology, energy, environmental monitoring etc. can perform more advanced analysis.

The methodology used to produce the ASTER GDEM involved automated processing of the entire 1.5-million-scene ASTER archive, including stereo-correlation to produce 1,264,118 individual scene-based ASTER DEMs, cloud masking to remove cloudy pixels, stacking all cloud-screened DEMs, removing residual bad values and outliers, averaging selected data to create final pixel values, and then correcting residual anomalies before partitioning the data into 1°-by-1° tiles. It took approximately one year to complete production of the beta version of the ASTER GDEM using a fully automated approach.

The ASTER GDEM covers land surfaces between 83°N and 83°S and is composed of 22,600 1°-by-1° tiles. Tiles that contain at least 0.01% land area are included. The ASTER GDEM is in GeoTIFF format with geographic lat/long coordinates and a 1 arc-second (30 m) grid of elevation postings. It is referenced to the WGS84/EGM96 geoid. Pre-production estimated accuracies for this global product were 20 meters at 95 % confidence for vertical data and 30 meters at 95 % confidence for horizontal data.

This was produced using ASTER data acquired from the start of observation to the end of August, 2008 in cooperation with the Japan-US ASTER Science Team. ASTER GDEM is now released and its distribution started, after the validation and the distribution site design.

ASTER GDEM tiles can be downloaded electronically from ERSDAC by visiting the link below: This web-based search system has 4 methods for tile selection. You can select tiles with one of the following methods.

The aim of the toolkit is to show
managers, scientists and technicians working in marine, terrestrial and
atmospheric environments how images collected from satellites and aircraft
(remote sensing) can be used to map and monitor environmental features or processes
and their change over time.

Marine remote sensing toolkit

Marine environments encompass a broad range of environments; however,
this toolkit focuses on coastal/inshore and oceanic/offshore water bodies,
seagrass and coral reefs, and mangroves.

The following diagram shows the spectral signatures of benthic bottom types using different sensor types.

Terrestrial remote sensing
toolkit

The “terrestrial” encompass a broad range of environments; this
toolkit focuses on a range of generic land cover types, which are found across
all ecosystems.

Atmospheric remote sensing
toolkit

Atmospheric environments encompass the envelope of air surrounding the
Earth, including its interfaces and interactions with the Earth's solid or
liquid surface.

The toolkit provides a selection of worked examples and industry contacts for the procedures necessary to map Marine, terrestrial and atmospheric ecosystem properties from remote sensing. The following listing presents examples of typical users:

Natural resource managers/policy makers - Can I use remotely sensed data (or a product derived from this) to map and monitor a terrestrial ecosystem health indicator in the range of environmental conditions experienced in the terrestrial environment I am responsible for?

Natural resource scientists/technicians - Which indicators of terrestrial ecosystem health can I accurately map and monitor in my terrestrial environment using commercially available remote sensing data and what are the basic resources, personnel and time required to do this?

Spatial information professionals - How can I use remote sensing to accurately map and monitor in my terrestrial environment using commercially available remote sensing data and what are the basic resources, personnel and time required to do this?

Students - How can remotely sensed data be used to map and monitor terrestrial ecosystem health indicator(s) in the range of environmental conditions typically experienced in the terrestrial environment?

General public - What type of information can be accurately mapped and monitored from remotely sensed data of terrestrial environments?

The Seamless Data Warehouse is
the ideal location to explore and retrieve data. U.S. Geological Survey (USGS)
and the Earth Resources Observation and Science (EROS) are committed to
providing access to geospatial data through The National Map. An approach is to
provide free downloads of national base layers, as well as other geospatial
data layers. These layers are divided into framework categories.

Places

Structures

Transportation

Boundaries

Hydrography

Orthoimagery

Land Cover

Elevation

The Seamless Data
Warehouse capabilities include:

Free downloads up to 3 Gigabytes of data in 250
Megabyte files per request: Users have unlimited access to
the interactive map and can make unlimited requests. The amount of coverage
area depends on the number of products selected for download. For example, if
NED 1 Arc Second is selected as the only product a user can download up to a 30
square degree area. But, if NED 1 arc second and NED 1/3 arc second are selected,
then the area available for download will be considerably smaller. To see the
various sizes of coverage area for each product, click on the List of Products
drop down on the right side of the viewing area and select the desired product.

User can define an area of interest by drawing a
box, defining coordinates, or use available templates to cut out the area: The first method of drawing a box
(square or rectangle) is best for defining a general area. The coordinates are
displayed, in decimal degrees, in the bottom left corner of the window as the
mouse is moved over the map. The second method of defining coordinates can be
used when the user wants a precise area and knows the corner coordinates. The
third method is the use of provided templates, such as 7.5 minute quadrangles.

Tiled Data Distribution System (TDDS) :
allows a user to access historical data from the EROS storage system. The
concept of The National Map Seamless Server is to provide the best available
data. High resolution orthoimagery, the best available will change
approximately every couple of years as new imagery becomes available. The older
imagery will be removed from The National Map Seamless Server and map services
and made available using TDDS.

Query tools are provided to acquire more
information about the an area of interest: An example of the two query tools
are Elevation Point and Elevation Profile. The elevation point tool allows a
user to click anywhere on the map interface and an elevation will be returned,
in feet, as well as the coordinates. The elevation profile tool will provide a
cross section graph between two points, in any direction.

Sample data map:

Tools to Access Data:

ArcGIS Toolbar

Mapping Services

Application Services

Tiled NED Tool

Inventory Search

Seamless Viewer

TNM Viewer

The Seamless Data Warehouse is always growing with new data,
tools, features, and much more.

NGDC's data holdings currently
contain more than 400 digital and analog databases, some of which are very
large. As technology advances, so does the search for more efficient ways of
preserving these data.

NGDC works closely with
contributors of scientific data to prepare documented, reliable data sets and
welcoming cooperative projects with other government agencies, nonprofit
organizations, and universities, and encourage data exchange.

The Data Centre continually
develops data management programs that reflect the changing world of geophysics
and welcoming your input to their programs and look forward to supplying your
data needs.

Now, the Latest Global Map of
Irrigation Areas (Latest version 5.0) is available as a FREE download. The map shows
the amount of area equipped for irrigation around the turn of the 20th century
in percentage of the total area on a raster with a resolution of 5 minutes. The
area actually irrigated was smaller, but is unknown for most countries. A
special note has to be made for Australia
and India where the map shows the total area actually irrigated. This is due to the fact that statistics
collected in Australia and India refer to actually irrigated area as opposed to
statistics with area equipped for
irrigation which are collected in most other countries. An explanation of
the different terminology to indicate areas under irrigation is given in the
glossary.

For the GIS-users the map is distributed in two different formats:

as zipped ASCII-grid that can be easily imported in most GIS-software that support rasters or grids;

and, to accommodate people who use GIS-software that doesn't support rasters or grids, as a zipped ESRI shape file.

The documentation of the map includes an explanation of the methodology, information per country, an assessment of the map quality, and references to the background and history of the irrigation mapping project. Users of Google Earth can see the Global Map of Irrigation Areas as an overlay by opening this file in Google Earth.

Sample Map 1

Sample Map 2

The map is generated
as a grid and distributed with the following characteristics:

Projection

Geographic

Number of columns

4320

Number of rows

2160

North Bounding Coordinate

90 degrees

East Bounding Coordinate

180 degrees

South Bounding Coordinate

-90 degrees

West Bounding Coordinate

-180 degrees

Cell size

5 minutes, 0.083333 decimal degrees

NODATA values

Cells without irrigation are characterised by NODATA (-9), it does not mean that there was no data for these cells

Easier Sharing, Attribute Table
Display, and New Presentation Tools Are Among Improvements

The most recent ArcGIS Explorer
Desktop release includes new features and enhancements to make it a more
powerful tool in an enterprise GIS, including content sharing via ArcGIS
Online, tabular information display, and new presentation tools. ArcGIS
Explorer Desktop is a free GIS viewer that enables the exploration and
visualization of GIS information.

The new version of ArcGIS
Explorer Desktop allows users to upload GIS content directly to ArcGIS Online
accounts, where anyone with Internet access can see it. Integrating ArcGIS
Explorer with ArcGIS Online and Portal for ArcGIS, Esri's on-premises cloud
expands its support for role assignment, creation of custom basemap galleries,
and organization-specific searches. Users can search shared content on ArcGIS
Online or private content hosted using Portal for ArcGIS.

Download SRTM 250m or 90m Digital Elevation Data (Version 4.1) The SRTM Data now available from CSI-CGIAR SRTM Data portal. This is Free, and all the data has been upgraded to version 4.1. This latest version represents a significant improvement from previous versions, using new interpolation algorithms and better auxiliary DEMs.

For quick and easy data downloads, this portal has a nice user-friendly web interface which provides users three flexible options to choose, in order to selecting multiple tiles for downloading.1. Multiple tile selection by clicking on tiles2. Drag the mouse-point on top of the world map and mark & select the tiles3. or, enter lat-long input coordinates.

In addition, you can switch between their different hosting servers, to select either HTTP or FTP downloads.

Just open the below image and see how easy it is !

The CGIAR-CSI GeoPortal is able to provide SRTM 90m and 250m Digital Elevation Data for the entire world. The SRTM digital elevation data, produced by NASA originally, is a major breakthrough in digital mapping of the world, and provides a major advance in the accessibility of high quality elevation data for large portions of the tropics and other areas of the developing world. The SRTM digital elevation data provided on this site has been processed to fill data voids, and to facilitate it's ease of use by a wide group of potential users. This data is provided in an effort to promote the use of geospatial science and applications for sustainable development and resource conservation in the developing world. Digital elevation models (DEM) for the entire globe, covering all of the countries of the world, are available for download on this site.

The SRTM 90m DEM's have a resolution of 90m and 250m at the equator, and are provided in mosaiced 5 deg x 5 deg tiles for easy download and use. All are produced from a seamless dataset to allow easy mosaicing. These are available in both ArcInfo ASCII and GeoTiff format to facilitate their ease of use in a variety of image processing and GIS applications. Data can be downloaded using a browser or accessed directly from the ftp site

UNEDP's Environmental Data Explorer
is the authoritative source for data setsused by UNEP and its
partners in the Global Environment Outlook (GEO) report and other integrated
environment assessments. Its online database holds more than 500
different variables, as national, subregional, regional and global
statistics or as geospatial data sets (maps), covering themes like Freshwater,
Population, Forests, Emissions, Climate, Disasters, Health and GDP. Display
them on-the-fly as maps, graphs, data tables
or downloadthe data in different formats.

The navigation within the
Environmental Data Explorer is fairly easy and straightforward. In most cases
you will have to select something (eg. a dataset, years, a module etc.),
before being able to continue in the process. After having done your selection,
you just have to click on the button to proceed in the process. If you like to
return to revisit or change the options you use the button.

If
your selected values are what you need, but you want to treat the data further
on your computer, then download the data in different version, ranging from
simple text to Excel and GIS formats.

Also, by clicking on the map
image, you will enter onto an Internet Map Server (IMS), which produces
on-the-fly a map covering your selected attributes (variable, region, time).
You can zoom into the map to get more details, identify a countries name and
value, produce a graph etc.

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